If cos (α + β) = 0, then sin (α – β) can be reduced to [NCERT Exemplar Problems](a) cos β(b) cos 2β(c) sin α(d) sin 2α

Answer: b Explaination: (b) cos (α + β) = 0 = cos 90° ⇒ α + β = 90° sin (α – β) = sin (α – β + β – β) = sin (α + β – 2β) = sin (90° – 2β) = cos 2β